Lock slider for slide fasteners



Nov. 19, 1940. e. DAHLIN LOCK SLIDER FOR SLIDE FASTENERS Filed March 22, 1939 IHUEHZDI' fizit. arneg Patented Nov. 19, 1940 UNITED STATES LOCK SLIDER FOR SLIDE FASTENERS Gustaf Dahlin, St. Catharines, Ontario, Canada,

assignor to Lightning Fastener Company, Limited, St. Gatharines, Ontario, Canada Application March 22, 1939, Serial No. 263,557

9 Claims.

My, invention relates .to improvements in lock sliders for slide fasteners of the type comprising a pair of stringers carrying interdig'itating members adapted to be engaged or disengaged by the I 3 movement of the slider therealong. The slider is particularly adapted for construction from nonmetallic, i. e. plastic, material but it may also serve eificiently for metallic fasteners.

The chief object of the invention is to provide a lock slider construction whereby the locking mechanism is operated by the normal actuation of a pull member which serves to draw the slider along theinterdigitating members, and to which the stress produced by actuation of the pull memher is taken by an integral part of the slider it- 'self, rather than by the locking mechanism. Such construction also provides a slider which may be readily assembled, difficult assembly having been an objectionable feature of prior devices.

It is also an object to devise a slider which has a minimum number of parts, which is neat in appearance, and which' is compact and has the delicate working parts protected to prevent them being rendered inoperative by catching in the material of the object upon which the fastener is used.

With the above and other objects, which will hereinafter become apparent as the specification proceeds, in view, the invention consists of the construction and arrangement all as hereinafter more particularly described and illustrated with reference to the accompanying drawing, in which:

Fig. 1 is a plan view of my improved slider showing a fragmentary section of a fastener;

Fig. 2 is a longitudinal sectional view thereof, on an enlarged scale, taken along the line 2--2 of Fig. 1,- and showing the slider in the locked position;

Fig. 3 is a view corresponding to Fig. 2 but showing the slider in the unlocked position;

Fig. 4 is a transverse sectional view of the slider taken'along the line 4--4 of Fig. 1;

Fig. 5 is a perspective view of the slider'bcdy without the track;

Fig. 6 is an inverted perspective view of the track thereof; and

Fig. 7 is a longitudinal sectional view of an alternative form of the slider showing the slider in the locked position corresponding to Fig. 2.

Like characters of reference designate corresponding parts in the different views.

Referring to the drawing, the conventional slide fastener with which my invention is-concerned comprises a pair of flexible stringers l and 2 provided with the interdigitating elements 3 adapted to be engaged and disengaged by a slider. The latter, broadly, consists of a body having upper and lower wings 4 and 5 which, with the diamond 6, define channels for'the guidance of the interdigitating members 3.

According to my invention, I provide on the upper wing 4 of the slider a pair of lugs I and 8 which may well be moulded integrally with the 10 rest of the slider when the latter is made of a plastic material. The lugs 1 and 8 are provided with undercut portions forming projections 9 and I 0 on the lugs which are adapted to engage shoulders H and I2 on a hollow track member i3, 15

by which an orthodox pull, suchas the ring I4, is retained on the slider. The lugs 1 and 8 are. provided'with ears I5 and i6, respectively, under which the ring I4 is caught when it is'positioned for opening and closing, respectively, of the fas- 20 tener, in which positions, it will be noted, the lugs 1 and 8, respectively, take the whole force transmitted to the slider by the ring l4.

Along the sides of the lug 1 are provided slots I1 and iii in the wing 4 in which are received 25 locking projections l9 and 20, respectively, of the track .13. A spring element 2|, which may well be a piece of spring wire having one flattened extremity 22, is secured to the lug H! with the flattened portion embedded therein and with its 30 free extremity lying in a slot 23 in the lug 1 and overlying the shoulder ll of the track.

As shown best in'Fig. 2, the spring 2| normally holds the track [3 against the wing 4 of the slider with the locking projections l9 and 20 protruding through the slots in thawing into engagement with the fastener elements 3 for locking of the slider. On grasping the pull ring i 4 to operate the slider, the track I3 is lifted, pivoting about the projection I!) on the lug 8 until the ring engages the ear [5 on the lug l, by which time the locking projections l9 and 20 have been withdrawn clear of the fastener elements 3 to permit the slider to slide therealong. On release of the pull I4 the spring 2| causes the locking projec- 45 tions to again engage the fastener elements for locking of the slider. It will be noted that the projections l9 and 20 are staggered longitudinally of the track, whereby each pro-' jection engages an interlocking element 3 of the 50 respective stringers to provide increased locking action and longer life for the locking means.

In order .to decrease the height of the track l3, the wing 4 may be given a concavity which accommodates the curved portion ofthe ring- I4 55 when it is positioned of the slider;

It is an important feature of the invention that the locking system may be readily assembled. In the form of the slider described above, the spring element may be readily installed in the lug 8 as shown in Fig. 5, whereafter, to complete assembly of the slider, it is merely necessary to insert the locking projections of the track in the slots at an angle with the wing l1 and I8, catch the shoulder ll under the free extremity of the spring 2| and then swing the the spring home to a position corresponding with that of the spring 2| in the first described embodiment. The projection of the spring 26 beyond the lug- 8 serves as an anchor for the track about which the track may rock. Such a construction operates similarly to that previously described and is also very simple to assemble.

By virtue of the construction of the improved slider, it may be very readily assembled without the necessity of complicated operations on very small parts and is hence economical to manufacture. Since substantially all the working parts are enclosed within the hollow track, they are protected .against accidental disarrangement' andthe slider also has a very neat appearance. The construction whereby the fastener opening or closing force is taken by the lugs on the slider,

rather than by track, also enablesthe track to be made of plastic material without its strength being objectionably low, and permits the bulk of the track to be reduced over that necessary in orthodox constructions;

While I have shown and described in this application two embodiments which my invention may assume in practice, it will be understood that these embodiments are merely for purposes of illustration and description and that various other forms may bedevised within the scope of my invention as defined in the appended claims. What I claim as my inventlonis:

l. A lock slider for a slide fastener comprising a body channelled for the passage of the fastener elements, a pair of track mounting lugs on the body, an elongated spring member secured at one extremity in one lug, a hollow track housing the lug and the spring member, a pivot for the track on said one lug, a shoulder disposed within the track adjacent the othenlug,

'a locking projection on the track passing through an orifice in the body and adapted to be held in locking engagement with the fastener elements by pressure of the free extremity of the spring on the shoulder, a pull member carried by the track for rocking the track about thepivot for lifting the locking projection out of engagement with the fastener elements, means for limiting the rocking movement of the track, and an ear on at least one of said lugs for directly engaging the pull member when the locking projection is disengaged from the fastener elements.

2. A lock slider for a slide fastener as claimed in claim 1 wherein the pivot for the track comprises a projection on the lug and a shoulderon the track engageable therewith.

reaction oi the wire spring, and the lug 3. A look slider for a slide fastener as claimed in claim 1 wherein the pivot for the track com-- prises an extension of the elongated spring member received in an orifice in the extremity of the track. I

4. A look slider for a slide fastener comprising a body channelled for the passage of the fastener elements, a pair of upstanding lugs on the slider body spaced apart longitudinally of the body, a

spring member secured at one endin one of the 10 lugs and passing freely through a slot in the other lug, a hollow track in which the lugs and the spring member are. received, a shoulder on one end of the. track engagedby the'free extremity of the spring member which passes 15 through the slotted lug, means on the track and the other lug for rockably retaining the track thereon, ja locking projection on the track adjacentthe slotted lug and passing through an orifice in the body and adapted to be held in 20 looking engagement with the fastener elements by the pressure of the spring on the track shoulder, a pull member carried by said track between the lugs for rocking the track about the lug to which the spring memberis secured for lifting the locking projection of the track out of engagement with the fastener elements, a projection on the slotted lug engageable with the shoulder on the track for limiting the lifting movement of the track, .and'an inwardly directed ear on each lug for directly engaging the pull member when the locking projection is disengaged from the fastener elements.

5-. A lock slider for a slide fastener as claimed in claim 4 wherein the means for retaining the track on said unslotted lug comprises a second shoulder on the track and a projection on the unslotted lug, I

6. A lock slider for a slide fastener as claimed in claim 4 wherein the means for retaining the track on said unslotted lug comprises an extension of the spring member beyond the unslotted lug received in an orifice in the track.

'7. A look slider for a slide fastener comprising a body channelled for the passage oi. the i'astener elements, a pair of upstanding'integral lugs thereon located in spaced relation longitudinally of the body, an inwardly directed ear on each lug, a spring strip secured-at one extremity in one of the lugs and lying substantially parallel to the body and projecting freely through a slot in the other. lug, a hollow track of temporarily deformable material housing. the lugs and spring, a pull member engaging the track between the lugs, a pair of locking projections on the track each adapted to engage one of the elements'of the respective series of interlocking elements of the fastener and projecting through a pair of orifices in the slider body ,disposed one so on either side of the slotted lug, a shoulder on each extremity of the track and located therewithin, a projection on the unslotted lug adapted to engage one track shoulder to serve as a fulcrum for the track, and a projection on the under the free extremity of the wire spring and snapping the other shoulder over the unslotted lug, the projection on the slotted lug serving to limit the motion of the track when the latter is lifted by means of the pull member against the serving as the sole means for'transmitting force from the pull member to the slider.

8. In a lock slider for a slide fastener, a body channelled tor the passage of the fastener elements, track mounting means thereon, a projection on each extremity of such means, a hollow track housing the mounting means, a shoulder disposed inwardly of each extremity oi the track and engageable with said projections for rockably retaining the track on the body, a locking projection on the track, and an elongated spring member underlying the track and having one extremity secured in the track mounting means and its free extremity in engagement with one of said track shoulders ior normally retaining the locking projection in operative position.-

9. In a lock slider for a slide fastener which includes a body channelled for the passage or the fastener elements, a pair of lugs on the body, a hollow track rockably mounted on said lugs, a pull member slidably carried on said track between the track and said body, fastener element locking means on the track, and an ear on at least one of said lugs engageable directly with the pull member for transmitting the full slider moving force from the pull member to the slider body.

GUSTAF DAHLIN. 

